Diagnosis of diabetes mellitus primarily consists in measuring the level of sugar in the blood. This study can be carried out both in a medical institution and at home with the help of a special device – a blood glucose meter. In addition to determining the level of sugar in the blood, there are several other methods for diagnosing diabetes mellitus – a glucose tolerance test, a test for glycated hemoglobin, a test for insulin levels and a blood test for C-peptide. All these tests raise many questions and the doctor does not always have time for detailed explanations. This article will tell you about what methods of diagnosing diabetes exist, why they are carried out, and how you can control your sugar level without leaving home.
Laboratory diagnosis of diabetes mellitus
There are generally accepted methods for diagnosing any type of diabetes, recommended by the World Health Organization (WHO). Of these, three mandatory analyses are required:
- blood for fasting sugar
- glucose tolerance test or blood sugar test 2 hours after eating
- analysis for glycated hemoglobin
And three additionalones that perform if necessary to clarify the type of diabetes mellitus:
- blood test for c-peptide or insulin
- blood test for antibodies
- genetic analysis
Let’s look at each analysis in more detail.
1. Blood sugar on an empty stomach
They can be taken from a finger (capillary blood) or from a vein. A blood sugar test is an early diagnosis of diabetes. Sometimes diabetes is asymptomatic and can only be detected by a blood test. Blood for sugar is taken not only when the characteristic symptoms of diabetes mellitus appear, but also during preventive examinations, as well as almost any visits to the doctor, even about ARVI. Early diagnosis of diabetes mellitus avoids complications and improves the prognosis of treatment.
Since the level of sugar in the blood rises after taking carbohydrates, blood is given in the morning on an empty stomach so that the food taken does not distort the result.
The table shows the data of an empty stomach blood test for the diagnosis of diabetes mellitus and borderline conditions:
A borderline condition is a violation of glucose tolerance, or prediabetes. With prediabetes, there are no clinical manifestations of the disease yet, but the absorption of sugar by the body’s tissues is already impaired. Most often, a violation of glucose tolerance accompanies obesity. Prediabetes is corrected without medication with a low-carb diet and sports. That is why it is very important to identify violations in time and take appropriate measures.
2. Glucose tolerance test
This diagnostic method will show how the human body regulates sugar levels. For the test, you need to take 75 grams of glucose on an empty stomach, diluting it in a glass of water. 2 hours after this, blood is given from a finger or from a vein.
The table shows blood test data 2 hours after fasting glucose intake in diabetes mellitus and borderline states:
3. Analysis for glycated hemoglobin
This is one of the mandatory methods for diagnosing type 1 and type 2 diabetes.
Hemoglobin is a protein found in red blood cells. Hemoglobin has the property of binding to blood glucose. In biochemistry, this reaction is called glycation. The more glucose in the blood, the more hemoglobin is glycated. Red blood cells live for 120 days (3 months), and then they are renewed. Accordingly, the blood test for glycated hemoglobin will reflect the sugar level for the last 3 months.
Thus, a blood test for sugar on an empty stomach and 2 hours after taking glucose will show us what is happening with sugar now, and glycated hemoglobin will reflect the history, that is, whether there were violations before.
The norm of glycated hemoglobin (HbA1c) in healthy people is from 4 to 6 %. All of the above is considered a pathology and is a sign of diabetes.
4. Blood test for c-peptide or insulin
This analysis is carried out in the case when they can not accurately determine the type of diabetes, and when the question of switching from tablets to insulin injections in type II diabetes mellitus.
First, you need to understand what C-peptide is and what it has to do with insulin. We already know that insulin is a hormone produced by the pancreas. At the same time, it does not immediately enter the blood, but accumulates in the cells in an inactive form, which is called proinsulin. With an increase in blood sugar, a chain of amino acids is broken off from proinsulin and it turns into insulin. This chain of amino acids is called a C-peptide. At the same time, the amount of C-peptide in the blood is 5 times more than insulin, since it lives 20 minutes, and insulin only 4 minutes.
For the diagnosis of diabetes mellitus, it is recommended to conduct a stimulated C-peptide test, that is, to have breakfast 2 hours before the diagnostic procedure. In this case, the amount of carbohydrates should be equal to 2-3 bread units.
To compare the indicators of a blood test for C-peptide, it is also advisable to pass an empty stomach test. In a healthy person, the C-peptide index after breakfast should be 3-4 times higher than on an empty stomach.
In type 2 diabetes, the C-peptide is elevated, and in type 1 it is reduced. There are also a number of diseases in which the level of C-peptide deviates from the norm, and this is the reason for finding out the causes of such deviations.
5. Blood test for antibodies
We are talking about antibodies to insulin, pancreatic cells and to the enzyme that is in these cells. This enzyme is called the long word glutamate decarboxylase (abbreviation GAD). In type 1 diabetes, the body perceives cells, insulin, and the GAD enzyme as foreign agents and destroys them. These processes begin to occur long before the appearance of a diabetes clinic. Symptoms appear when the cells of the pancreas are destroyed by at least 70%.
The material for this analysis is venous blood donated on an empty stomach. The appearance of antibodies is a characteristic diagnostic sign of type 1 diabetes mellitus.
6. Genetic analysis
It is performed for type 1 and type 2 diabetes if close relatives have this disease. It is noted that if one of the parents has diabetes, then the child in 5-10% of cases can also get sick, and if both parents are sick, this probability increases to 70%. This study identifies the genetic risks of the disease. The material for genetic analysis is blood from a vein.
Here is a brief description of laboratory methods for the diagnosis of diabetes mellitus. At the same time, some of them will have to pass in the future, in order to assess how much it was possible to keep the sugar in the norm.
Type 2 diabetics are recommended to donate blood for sugar 1-2 times a month. It is also advisable to donate blood for glycated hemoglobin once every 3 months, in order to track the history of sugar levels during this period of time.
Diabetics of type 1 must necessarily use a blood glucose meter several times a day. Yes, and type 2 diabetics are also recommended to periodically conduct such studies at home. Even if you feel well, it is advisable to monitor your blood sugar levels at least once a month. Measurements should be taken in the morning on an empty stomach, then BEFORE each meal and 2 hours AFTER. Another measurement is carried out at night in 2-3 hours. So you get a more complete picture of the daily fluctuations in sugar. To evaluate the result, use special tables (see above).
Thus, we have come to the conclusion that every diabetic needs to understand all the subtleties of the work of a home blood glucose meter, since now this device should always be at hand.
Algorithm for diagnosing diabetes using a blood glucose meter
Currently, there are a variety of gadgets for measuring sugar levels. Some of them have additional convenient options and can connect to a computer or mobile phone.
The algorithm for diagnosing diabetes mellitus in all blood glucose meters is almost the same:
- It is necessary to insert the lancet into the perforator to the required depth. For thin skin – 2-3 mm, for coarser 3-4 mm.
- Insert the test strip into the device. After identification, the device will be ready for operation
- Wash your hands with soap and water. It is better not to disinfect the finger, as the results may be distorted.
- Prick your finger, massage it to improve blood circulation. Remove the first drop of blood with a napkin, as the result of the following doses will be more reliable.
- The second drop is attached to the test strip or brought to it (modern devices themselves draw in a drop).
- After a few seconds, the result will appear on the blood glucose meter screen.
There are also disadvantages to the blood glucose meter. We are not talking about the painfulness of the procedure (although doing a finger puncture with a lancet of a blood glucose meter is much less painful than in the laboratory). The fact is that monitoring of sugar levels, especially at the beginning of treatment and especially for type 1 diabetics, is carried out up to 10 times a day. Imagine how uncomfortable it is to do this while at work, for example.
There is a more convenient and functional device that allows you to monitor the level of sugar around the clock. It consists of a sensor that is attached to the hand (the needle is very thin there, and you will not feel a puncture), and a sensor that should be at your fingertips. Glucose measurements are taken every minute, and the sensor captures and stores this data in memory. The sensor can be attached to the hand for up to 2 weeks, after which it must be changed. This device, of course, is not necessary for compensated diabetes mellitus – here you will limit yourself to episodic measurements of sugar, but for uncompensated diabetes, it is simply irreplaceable. Unfortunately, you will not buy it in the public domain at the pharmacy, most likely you will have to order it through the online store.
There are also blood glucose meters with a laser piercing device, which greatly simplifies the analysis procedure.
Regardless of which diagnostic device you choose for home use, it is important to remember that timely diagnosis of diabetes can save your health and even life.
Control your blood sugar and stay healthy!